CHECK NAMES

CHECK NAMES (LET)

Let Subcommand

Given a list of names, check if any names are not already defined.

Sometimes when writing general purpose macros it may be useful to know if certain names have been defined. This can be either because certain variables or parameters are expected to be defined or because you want to use a particular name and you want to ensure that it is not already being used.

LET <iflag> = CHECK NAMES <name1> <name2> ... <namek>
where <name1> <name2> ... <namek> is a list of 1 to k names;
and     <iflag> is a parameter where the status is saved.

If all names are already defined, <iflag> will be set to 1. If one or more names are undefined, <iflag> will be set to 0.

LET IFLAG = CHECK NAMES Y X

The CALL EXIT and CALL EXIT ALL commands were added to allow you to exit a macro. The status flag from the CHECK NAMES command can be used to determine whether you want to exit from a macro or continue.

None

None

CHECK TYPES	= Check the types for a list of names.
CHECK EQUAL LENGTH	= Check whether a list of variables have the same number of elements.

Data Management

2015/06

skip 25
read berger1.dat y x bat
let iflag = check names y x bat s
    

The following output is generated

***** ERROR IN CHECK NAME--
      NAME S        WAS NOT FOUND IN THE CURRENT NAME LIST.
 
THE STATUS FLAG FOR CHECK NAME =        0